Alleyways and crime in Denver, Colorado census blocks

An alley is a narrow passageway between or behind buildings, which allows for pedestrian or vehicular activities. It follows that there are competing expectations for how this characteristic of the built environment shapes crime in geographic units. The fundamental tenets of environmental criminology suggest that alleys might breed crime problems because of their ability to increase criminal opportunities. On the other hand, the foundational principles of New Urbanism suggest that alleys might have the opposite effect to the extent that alleys operate as social conduits and foment social capital. Accordingly, for the present study, we conduct a block analysis of crime, alleys, land uses, and sociodemographic characteristics in Denver, Colorado. We estimate negative binomial regression models of both violent and property crime and find strong evidence for the environmental criminology perspective, with the effects of alleyways being relatively strong juxtaposed to other covariates in the models. We also find that various factors, including ethnic heterogeneity, retail and commercial space, and surrounding poverty, moderate the effect of the presence of an alley. The implications of these findings for criminology, urban studies, and public policy are discussed.